基于FARSITE模型的丰林自然保护区潜在林火行为空间分布特征

Spatial distribution characteristics of potential fire behavior in Fenglin Nature Reserve based on FARSITE Model

将FARSITE火行为模型应用于丰林自然保护区林火行为预测,并根据Rothermel和Rinehart制定的林火行为等级标准,编制潜在林火行为空间区划图,以探讨林火行为的空间分布特征。研究结果表明:在有可能、易发生和极易发生3个森林火险等级下,丰林自然保护区林火行为主要分布在Class I和ClassⅡ等级上,使用手工工具可能从火头控制火势蔓延;林火行为等级空间分布特征较为明显,ClassⅢ等级的火行为主要分布在区域中东部,ClassⅡ主要分布在区域中部,而Class I则主要分布在区域四周;高强度林火行为主要分布在可燃物模型为FL-Ⅰ和FL-Ⅱ,海拔为300—400 m、坡度为平坡和缓坡、坡向为阳坡上。高强度林火发生在接近道路与居民点500 m的区域内分布面积明显高于分布在距离道路居民点500—1000 m和1000—1500 m区域。

Forest fire plays an important role in determining the species composition,age structure,and ecological processes of forest ecosystems.The high forest fuels accumulation coupled with a warmer and drier climate in recent decades makes the study of potential fire behavior of great practical significance.However,most forest fire behavior studies have been conducted at the plot-to-stand levels that cannot meet the landscape-to-regional levels fire management requirements.Researchers and managers are increasingly interested in spatially explicit fire simulation models that can simulate fire spread processes at larger spatial and temporal scales for use in fire management,planning,and scientific analyses.Thus,the main objective of this study was to simulate the potential fire behavior in Fenglin Nature Reserve under the low,moderate and extreme fire danger ratings with a spatially explicit fire behavior simulation model,FARSITE（Fire Area Simulator）.According to the fire severity danger standard developed by Rothermel and Rinehart,potential fire behavior zone maps were obtained based on the FARSITE simulation results.Main conclusions from this study were drawn： 1） Under the low fire danger rating,the potential burned areas of classes Ι,Ⅱ,Ⅲ for Fireline intensity were 17765.82 hm2,105.5 hm2,and 1.89 hm2,respectively.The potential burned areas of classes Ι,Ⅱ,and Ⅲ for Flame length were 17722.71 hm2,61.47 hm2,and 0.81 hm2,respectively.under the moderate fire danger rating,the potential burned areas of classes Ι,Ⅱ,Ⅲ for Fireline intensity were 16349.04 hm2,1483.92 hm2,and 6.75 hm2,respectively.The potential burned areas of classes Ι,Ⅱ,and Ⅲ for Flame length were 15785.10 hm2,2033.37 hm2,and 21.24 hm2,respectively.Under the extreme fire danger rating,the potential burned areas of classes Ι,Ⅱ,Ⅲ for Fireline intensity were 7950.78 hm2,7540.38 hm2,and 2351.52 hm2,respectively.The potential burned areas of classes Ι,Ⅱ,and Ⅲ for Flame length were 7108.65 hm2,7263.54 hm2,and 3470.49 hm2,respectively.The results showed that under the low,moderate and extreme high fire danger rating,the potential fire behavior were mainly distributed on the Class Ι and class Ⅱ that can be controlled by persons using hand tools at the head or flanks of fires;2）The spatial distribution characteristic of fire was obvious.The Class Ⅲ were mainly distribution on the mid-eastern region,Class Ⅱ were mainly distribution on the middle region,and Class Ι were widely distribution on the edge of the region;3）The high fire danger areas were distribution of the fuel model FL-Ι and FL-Ⅱ,elevation gradient 300—400 m,slope gradient flat slope and gentle slope.High intensity fire within 500 m road and settlement was much more than that between 1000 and 1500 m;4） The result may give a useful suggestion for fire and fuel management in Fenglin natural reserve.In the future the research should concentrate on validating the simulated results using observed fire behavior in Fenglin Nature Reserve.